Peel the 3 lb Yukon Gold potatoes peeled and cut into 2-inch chunks and cut them into uniform 2-inch chunks. This ensures they cook evenly and at the same rate.

Place the 3 lb Yukon Gold potatoes peeled and cut into 2-inch chunks chunks in a large pot and cover with cold water by at least 1 inch. Add a generous pinch of kosher salt (the water should taste lightly salty, like the sea). Bring to a boil over high heat.

Once boiling, reduce the heat to medium and cook the 3 lb Yukon Gold potatoes peeled and cut into 2-inch chunks until completely tender — a fork or knife should slide in with zero resistance, about 18–22 minutes. Do not undercook; undercooked 3 lb Yukon Gold potatoes peeled and cut into 2-inch chunks lead to lumpy mash.

While the 3 lb Yukon Gold potatoes peeled and cut into 2-inch chunks cook, warm the ¾ cup heavy cream and ¼ cup whole milk together in a small saucepan over low heat until steaming but not boiling. Keep warm. Room-temperature or warm dairy is key — cold dairy will make the mash gluey and dense.

Drain the 3 lb Yukon Gold potatoes peeled and cut into 2-inch chunks thoroughly in a colander and let them steam-dry for 2 minutes. Shake the colander gently to release as much moisture as possible — dry 3 lb Yukon Gold potatoes peeled and cut into 2-inch chunks absorb 6 tbsp unsalted butter cut into cubes and ¾ cup heavy cream better.

Pass the hot 3 lb Yukon Gold potatoes peeled and cut into 2-inch chunks through a potato ricer back into the warm pot (or mash with a potato masher for a slightly more rustic texture — avoid a blender or food processor, which will make the mash gluey).

Place the pot over low heat. Add the 6 tbsp unsalted butter cut into cubes cubes a few at a time, folding them in gently with a wooden spoon or spatula until fully melted and incorporated before adding the next batch.

Gradually pour in the warm ¾ cup heavy cream and ¼ cup whole milk mixture, folding gently until the mash reaches your desired consistency. You may not need all of the liquid — stop when it's silky and smooth. Season with 1½ tsp kosher salt and ¼ tsp white pepper freshly ground, tasting as you go.

Remove from heat and drizzle in the 2 tablespoons of white truffle oil high quality, folding it in gently. Taste and adjust 1 ½ tsp kosher salt. The truffle flavor will bloom as the mash sits for a minute — resist the urge to add too much oil at once.

Transfer to a warm serving mixing bowl. Optionally, drizzle with an extra splash of white truffle oil high quality, scatter fresh fresh chives finely chopped over the top, and shave fresh fresh black or white truffle shaved with a mandoline or Microplane directly over the dish if using. Serve immediately.